<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>buttonEvent</title>
    <script src="./buttonEvent.js"></script>
    <style>
        #box1 {
            width: 300px;
            height: 300px;
            background-color: orangered;
        }
        
        #box2 {
            width: 200px;
            height: 200px;
            background-color: purple;
        }
        
        #box3 {
            width: 100px;
            height: 100px;
            background-color: skyblue;
        }
    </style>
</head>

<body>
    <button id="button" style="width: 200px;height: 100px;">button</button>
    <div id="box1">
        <div id="box2">
            <div id="box3">

            </div>
        </div>
    </div>
    <button id="add" style="width: 200px;height: 50px;margin:50px 0px 0px 0px">add</button>
    <ul id="ul">
        <li class="link">1</li>
        <li class="link">2</li>
        <li class="link">3</li>
    </ul>
</body>

</html>